where/what is the most/best distro agnostic, desktop-environment agnostic, window-manager agnostic, login-manager agnostic, init agnostic, fundamental basic simple clean minimal ubiquitous method of having the following command* be the desktop background wallpaper? * (or whatever other command is used for setting the background "image", like whatever, or whatnot.) ~ but where in the system's configs to put that.

I presume putting that xscreensaver's galaxy command into .fehbg will fail. but i'm looking for something more core basic fundamental minimal than relying on feh anyway (because i want the shiny galaxy background by default).

as simply as i can put the question (after a lot of attempts):

where in the system configs does the command to set the default background image go?

ps.(agnostic's a silly choice of word there, but seems a readily understood convention. my mental thesaurus does want to reach for something more like... ambivalent(?), non-specific, unrelated... something like that. please do feel free to mention as an aside if you think you can offer me clarity/correction on any of that too.)



-- posting before i over-work this question any more.

I gather you're asking two questions:

1. What is the most "fundamental basic simple clean minimal ubiquitous" place to indicate a command should be run when starting an Xorg server.
2. How to make the "galaxy" xscreensaver the background rather than a screensaver.

I'm insufficiently experienced with xscreensaver to provide any advice for the second question. At first blush I'm concerned it might not be cleanly possible. Hopefully someone else knows.

However, for the question of where to set such a command, should you be able to make it:

One of the more "fundamental basic simple clean minimal ubiquitous" methods of starting an Xorg server is with the `xinit` command. Some other methods (e.g. `startx`) are wrappers around this. Per `man xinit`, by default it executes `~/.xinitrc`, and so people who start Xorg this way often place some command to set the background in `~/.xinitrc`. If you go down this road, be warned that by default Xorg will exit once `~/.xinitrc` returns, and so people usually throw something long-lasting like their window manager at the end in a blocking manner. You can probably query your preferred search engine for "xinitrc" for more, including examples.

If you utilize `xinit` (or `startx`, etc) I'd argue there aren't any more "fundamental basic simple clean minimal ubiquitous" options to set a background. If you use some other method of starting Xorg which ignores `~/.xinitrc`, it won't have a "fundamental basic simple clean minimal ubiquitous" overlap with `~/.xinitrc`, and you'll have to start looking at login manager / desktop environment / etc specifics.

depends how you start X.
on my system, it would be ~/.xinitrc

also, on my system, /usr/lib/xscreensaver is not in PATH, so i have to issue the full path to start it, aprt from that it works as expected.
unless, of course, some stoopid desktop environment simply paints over the root window.